Geometrical instrument



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- B. BARTHOLOMEW I GEOMETBICAL INSTRUMENT Filed March 16 1922 A E/ 4/ -W menfroz Bruce Bart/z aw Patented Aug," 14, 123.

BRUCEJBABTHOLOMEW, OF BERKELEY, CALIFORNIA.

GEOMETRICAL rns'rnuivrnn'r.

Application filed March 16, 1922. Serial No. 544,130.

3 l a part of this specification:

The figure is a plan view of my instru ment.

My geometrical instrument includes a plurality of divider and ruler bars 1, and a pair of pivot bars 2 and 3 inclined to said bars, which pivot bars are pivoted to the bars 1 by pivots t and 5 respectively, in such relation that the bars 1 are parallel to each other and the bars 2 and 3 are parallel to each other. The ends 6 of the bars 1 are pointed and in said ends of said bars are punch holes 7 respectively. Oneend of each of the pivot bars 2 and 3 is extended for a considerable distance beyond the outermost divider bar in orderthat these extended ends may be grasped by the operator of the instrument.

Thus the instrumentimay be readily manipulated. It will be noticed that these pivot bars lie relatively close togethere so thattheir corresponding'extended ends readily form a hand grip. I I v In the presentembodiment of my inven .tion I" have shown eight bars When it is desired to divide a surface into seven equally spaced divisions the points 6 of the bars 1, 49 2 and 3 are swung on their pivots until the two outermost bars 1 are placed on the surface at the outermost points of the distanceto be divided, and the points 6 of the intermediate bars 1 will locate the intermediate points. The points may be marked on the metal surface by scratching the surface with the points 6.

By swinging the bars 1, 2 and 3 on their pivots, thebars 1 may be spaced at-difi'erent 50 distances 'apart and used as rulers for ruling ofi parallel lines at corresponding distances apart. r

The points of rivets may be laid oil on metal work by first locating said points with the bars 1 and then punching the points on the work with a punch through the holes 7 Havingdescribedmy invention, I. claim:

A geometrical instrument comprising a plurality of divider and ruler bars so arranged that they are constantly held in parallel relation, a pair of pivot bars pivoted to each of said divider bars and extending at an angle to the latter, said pivot bars being so arranged that theywill constantly be in 65 parallel relation. said pivot bars also extending for aconsiderable distance beyond the outermost divider bars, each of said divider bars being pointed at one end and having a *hole at its sharpened end, said holes extend- 7 ing'througheach divider bar in a direction at right angles to the; plane of said pivot bars, r

. In testimony Bacon eanrrror oiv nw.

whereof I afiix my signature. 

